Summary/Abstract Older adults often face important decisions more complicated than those usually studied in the laboratory, where choices are typically between immediate and delayed outcomes or between certain and probabilistic outcomes. In research with younger adults, such simple choices are often studied under the rubric of self-control, but recent findings suggest that rather than being a single construct, self-control may be better thought of as a collection of skills and abilities. Even fundamental decision-making processes (e.g., delay discounting or intertemporal choice; probability discounting or risky choice) may be more diverse than originally thought. With respect to age- related differences in these fundamental processes, moreover, there is a striking lack of consensus as to what changes occur as people age. We hypothesize that this picture can be greatly clarified by taking into account the presence of sex differences and income inequalities. Once the picture has been clarified, we will be well- positioned to study how fundamental decision-making processes combine in complex choice situations that are more like those that older adults, as well as younger adults, encounter every day. Therefore, Specific Aim 1 will study simple inter-temporal and risky choices involving gains and losses with the goal of understanding the structure of these fundamental decision-making abilities (e.g., the extent to which the abilities reflect a general impulsivity factor) and whether the relations among them differ in younger and older adults, thereby providing a baseline against which we then will compare the relations among abilities in more ecologically valid situations. Aim 2 will examine decision-making when choices involve outcomes that are both delayed and probabilistic, as in investments and many other financial decisions. Aim 3 focuses on decision- making when the outcomes involve both gains and losses that occur at different points in time, as in many health decisions (e.g., diets and vaccinations). Aim 4 examines choices with outcomes that differ qualitatively as well as in their time of occurrence, as when people choose between taking a vacation now or saving the money to purchase some desired good later. We plan to examine age-related differences with the goal of determining the strengths and weaknesses in older adults? decision-making in all of the preceding ecologically valid situations. For each Aim, we will recruit participants to be tested in the laboratory using computerized tasks to assess the subjective values of potential outcomes as well as online using questionnaires previously validated in the lab. Our studies will be guided by the hypothesis that decisions involving outcomes with multiple attributes are more cognitively demanding and therefore more sensitive to age-related differences in basic cognitive abilities. These studies will also test new models of decision-making that we have developed for ecologically valid situations, models we believe will inform our analysis of age-related differences. Finally, we will examine the interaction of sex and income differences with age-related changes in decision-making, all as part of our effort to identify potential targets of interventions such as ?nudges? to help older adults compensate for any specific weaknesses.